Prime Meridians

The choice of the prime meridian (0° longitude) is, of course, completely arbitrary. Here in the U.S., it is not uncommon to find 18th & 19th century maps and navigational aids showing the prime meridian going through Philadelphia or Washington, D.C. In October 1884, the International Meridian Conference convened in Washington, D.C. At that conference, 22 of 25 nations voted to make the longitude line through Greenwich, England the internationally recognized Prime Meridian (0° longitude). Santo Domingo voted against the resolution, and France and Brazil abstained.